Sinner gave the best indication yet that he is in the right mental state to prosper in New York after a gritty three-set win over home favourite Tommy Paul in the fourth round.

The world No.1 came into the tournament under a black cloud after it was revealed he had escaped a ban, despite failing two anti-doping tests earlier this year.

He was not challenged in his opening three rounds but did come under fire from the 14th seed on Arthur Ashe Court, holding firm to post a 7-6 (7-3) 7-6 (7-5) 6-1 win.

That result sets up a mouth-watering last-eight tie with Medvedev.

The Italian came from two sets down to win a maiden grand slam title in Melbourne in January, although the Russian did exact some revenge with a quarter-final win at Wimbledon in July.

“I can be very proud today, it was a tough opponent,” said Sinner.

“I can be very happy to be in the next round.

“It’s going to be a lot of running, so hopefully I’ll be ready physically, it is going to be a physical match.

“I won in Australia, he did well in Wimbledon over five sets. Hopefully it is going to be a good match.”

Medvedev could not have had it much easier against Portuguese Nuno Bourges, with a rogue fire alarm only stalling the inevitable.

The 2021 champion dropped just four games in a 6-0 6-1 6-3 success on Arthur Ashe.

With Carlos Alcaraz and Novak Djokovic out, Sinner appears to be the main obstacle between Medvedev and a second US Open title.

“I will try to think more about Wimbledon than Australian Open,” Medvedev smiled. “But against Jannik, we had some tough matches.

“I feel like in a way we know our game, what we will try to bring on the table.

“I know if I want to beat him, I need to be at my best.”

Play in Medvedev’s match had to be stopped after a fire alarm went off in the building housing Hawkeye - the electronic line calling system.

With Flushing Meadows relying completely on the technology for line calls - line judges having been dispensed with, play was delayed for around six minutes. 

Meanwhile, Britain’s Jack Draper booked a place in his first grand slam quarter final as he demolished Tomas Machac 6-3 6-1 6-2.

Draper, having yet to drop a set in his opening four matches, will next face Australian Alex de Minaur.

“I just need to keep going; I love playing here in New York, and I will just go through it again,” he said.

“I love playing on these big stages, I look forward to coming out again on Wednesday.”

Meanwhile, de Minaur says he wasn’t expecting to get this far into the competition.

“It’s been a whirlwind. The last seven, eight weeks, I’ve dealt with a lot of emotions, a lot of experiences that have taken a big chunk of my energy and resources,” he said.

“Coming in, I didn’t have too many expectations. The hip wasn’t close to 100 per cent. It wasn’t feeling amazing. I was just going to go out there and see what I was able to do.

“Slowly it’s been feeling better and better each day.

“So, all of a sudden, everything has happened with the draws, a lot of upsets, and you’re staring at this opportunity.”

AAP